COLORADO SPRINGS, Colo. — Boeing Phantom Works of St. Louis was awarded a $5 million contract from the U.S. Air Force to develop and operate two experimental cubesats that will carry space weather payloads, a Boeing official said April 13.

The company will spend the next year building the 4-kilogram spacecraft for the Air Force Space and Missile Systems Center’s Space Experimental NanoSat Experiment (SENSE) program, Todd Citron, Boeing’s director of advanced space and intelligence systems, said during a media briefing here. The satellites would be ready for launch in mid-2012, according to documents posted on the Federal Business Opportunities website.

The contract comes about a year after Boeing was tapped by the U.S. National Reconnaissance Office (NRO) to build as many as 50 of the tennis ball canister-sized spacecraft buses for the Colony 2 research program.

The U.S. military and intelligence community in recent years have become increasingly interested in small satellites thanks in part to technological advancements that have enabled smaller and smaller spacecraft components. Cubesats, which measure 10 centimeters on each side, were pioneered by the academic community and have become the standard for the very smallest of satellites. A rocket launching a more conventional satellite can accommodate dozens of cubesats as secondary payloads.

The Air Force began looking at cubesats last year as a way to meet some of the requirements developed for the now-dismantled National Polar-orbiting Operational Environmental Satellite System that it was developing with the National Oceanic and Atmospheric Administration and NASA. The SENSE program will study electron density profiles and atmospheric scintillation that can affect radio frequency communications, according to documents posted on the Federal Business Opportunities website.

For both the SENSE program and the Colony 2 program, Boeing is building so-called 3U cubesats that are the size of three 10-centimeter cubes connected end to end. The satellites will be built at Boeing’s Huntington Beach, Calif., facilities.

“It’s a pretty exciting area because of what technology is enabling us to do,” Citron said. “These are fairly small envelopes, but at the same time, with the way Moore’s Law has worked with iPads and things like that, the same technology advances apply to satellites, and the ability to get three-axis [stabilization] into that small form factor is pretty exciting.”

Meanwhile, the NRO’s first two Colony 1 cubesats were carried to orbit in December by a Falcon 9 rocket built by Space Exploration Technologies Corp. (SpaceX) that also carried the first Dragon capsule to orbit. Several more Colony 1 spacecraft were planned to fly this year on a Falcon 1e rocket, but SpaceX recently discontinued that launcher to focus its efforts on the larger Falcon 9 and a planned heavy-lift variant. NRO spokesman David Waltrop was unable by press time to say when and how these spacecraft will be carried to orbit.

For the NRO’s Colony 2 program, Boeing in February 2010 was awarded a contract to deliver 10 3U cubesat buses with options for as many as 40 more spacecraft. Waltrop was unable to provide launch information for these spacecraft as well.